The invention relates to a restraint belt for vehicle occupants. More particularly, the invention pertains to an inflatable restraint belt having an air bag module provided on the lap belt.
U.S. Pat. No. 3,866,940, DE-A 2 358 070 and DE 94 18 721 U1 disclose three-point restraint belts for motor vehicles, in which an airbag is fitted on the lap belt portion of the restraint belt. The lap belt runs from a mount on the outside of the motor vehicle to the belt buckle. The lap belt is deflected there and continues as the shoulder belt which typically ends in an automatic retractor.
However, these arrangements have the disadvantage that when the airbag in the lap belt is triggered, the lap belt is moved by the airbag away from the occupant. As a result, the restraining action of the belt system is neutralized. It is even possible for this to cause xe2x80x9cslipping throughxe2x80x9d (submarining) of the occupant. The same disadvantage may occur if a customary, standard lap belt is used.
The present invention provides an inflatable lap belt that maintains the restraining action of the belt after inflation of an airbag attached to the belt. According to the present invention, a restraint belt for vehicle occupants is provided. The restraint belt comprises a restraint belt which runs in the lap of the occupant as a double belt. The double belt includes a first section that bears directly on the body of the occupant, and a second section that at least partially overlies that side of the first section which is not in contact with the body of the occupant. The first section merges (i.e., is integrally connected) into the second section at a belt-deflecting point. An airbag module is fitted to the second section of the double belt. The airbag module includes a pocket for retaining the airbag.
The present invention is configured so that the effect that the second section of the restraint belt, which section lies at least partially in front of or above the first section, moves away from the occupant during the deployment phase by the reaction forces of the airbag, which is fastened to it. However, the first section is tightened at the same time. Therefore, in addition to the restraining effect of the airbag, the double belt results in a tightening effect in the restraint belt.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed.
This restraint system according to the invention can be used on all seats in vehicles, cars, trucks, including buses and airplanes. At present there are either no restraint systems or inadequate restraint systems particularly on the rear seats in cars and on seats in buses. This is also true of the driver""s seat in buses and trucks where the steering column is situated at a very steep angle. As a result, known airbag systems are not able to function adequately.
In one embodiment of the present invention, the restraint belt is arranged so that the double belt runs over the thighs of the occupant and the first section and the second section lie one above the other. This allows the airbag to deploy vertically upwards in the chest region, so that, on the one hand, it does not strike the occupant but, on the other hand, the airbag is not from spreading out by vehicle subassemblies.
In another embodiment, a three-point belt is provided in which a belt-deflecting point is provided in the region of the belt buckle, which is arranged at the customary location. The shoulder section of the belt merges into the first section of the lap belt at the belt-deflecting point.
However, in an alternative embodiment, the restraint belt may be designed just as a lap belt. In this embodiment, the belt-deflecting point for the transition of the first section into the second section is provided on the belt buckle.
The airbag module may be fastened on the second section of the lap belt by means of a pocket which is fitted onto the said second section between two fixing points, i.e. the airbag module is arranged between these fixing points. The fixing points may be displaceable in their position. It is thereby possible to displace the airbag module laterally and to adapt the position thereof to occupants of differing sizes.
Furthermore, it is expedient for a gas generator to be fastened to one side of the restraint belt and to be connected to the airbag via a gas supply line. The gas generator may, for example, be arranged under the seat or on the seat, on the vehicle body, on the floor or in the trunk of the vehicle.